1. Field of the Art
This invention relates to a pilot type electromagnetic valve with a simplified power supply assembly.
2. Prior Art
It would be acknowledged without any exemplification in particular that there is well known in the art the so-called pilot type electromagnetic valves which have, in combination with a main valve section with a main valve body for switching the flow direction of a main fluid, an electromagnetically operated pilot valve section for switching the position of the main valve body by the action of a pilot fluid pressure.
In the known pilot type electromagnetic valve of this sort, electric power is supplied to the pilot valve section through a printed wiring board which is mounted on a pilot valve assembly, the printed wiring board having electrical parts such as resistors, indicator lamps, a counter emf inhibitor and so forth assembled into a printed power supply circuit.
In this connection, it has been the usual practice to make electrical connections between the printed wiring board and the pilot valve section by way of a predetermined number of jack type terminals which are provided on the part of the printed wiring board, and pin type coil terminals projected from a solenoid coil in the pilot valve section for insertion into the jack terminals by press-in fitting engagement therewith. Therefore, upon inspection or replacement of the pilot valve section, each time there arises a necessity for unplugging and plugging the coil terminals from and into the jack terminals on the printed wiring board. These troublesome unplugging and plugging procedures are not only time-consuming but also very likely to cause bending deformations or breakage or other damages to the pin type coil terminals which are subjected to distorting or straining forces each time when they are unplugged and plugged in.
Besides, a certain type of electromagnetic valve is required to ground the pilot valve by way of a grounding terminal which is provided on the printed wiring board. In such a case, it is desirable to employ an arrangement which will permit one to connect the pilot valve section to the grounding terminal securely in a facilitated manner.